Because of the vaccine, cases of acute (short-term) hepatitis B have decreased by a lot in the United States. But chronic (long-term) hepatitis B is still common — up to 2.2 million people in the United States have it. Chronic hepatitis B can lead to serious liver problems — and even death.

Hepatitis B is a liver disease caused by a virus. There are 2 types of hepatitis B:

Acute (short-term) hepatitis B

Chronic (long-term) hepatitis B

Many children who get acute hepatitis B don’t have any symptoms, but most adults do. Symptoms may include:

Fever

Feeling tired

Upset stomach and throwing up

Not feeling hungry

Dark pee or clay-colored poop

Pain in the muscles, joints, and stomach

Jaundice (yellow skin or eyes)

Acute hepatitis B symptoms usually last a few weeks — but they can last as long as 6 months.

If the acute hepatitis B infection does not go away after 6 months, it’s considered a chronic hepatitis B infection. Most people who have chronic hepatitis B don’t have symptoms at first. But chronic hepatitis B is a lifelong illness that can lead to serious — and possibly deadly — liver problems, like:

Cirrhosis (scarring of the liver)

Liver cancer

Liver failure

Hepatitis B spreads through blood, semen, or other body fluids. Hepatitis B can spread from mother to child during birth — and when someone:

Adults at increased risk for hepatitis B

Adults who are at risk for hepatitis B can also get vaccinated. The vaccine is given in 3 doses. The second dose is given 1 month after the first dose, followed by a third dose 6 months after the second dose.

You may be at risk for hepatitis B if you:

Have diabetes

Have sex or live with someone who has hepatitis B

Have sex with more than 1 partner

Have an STD (sexually transmitted disease)

Are a man who has sex with men

Use drugs with needles

Could come into contact with blood at work (like in health care)

Get hemodialysis treatment for kidney problems

Travel to countries where hepatitis B is common

If you’re age 18 and older and at risk for both hepatitis B and hepatitis A, you may be able to get a combination vaccine that protects against both diseases. You may be at risk for both diseases if you:

Are traveling to certain countries where hepatitis B is common

Are a man who has sex with men

Use drugs

Talk with your doctor about how to protect your family from hepatitis B.

Side effects are usually mild and go away in a few days. They may include:

Soreness or redness where the shot was given

Fever

Serious side effects from the hepatitis B vaccine are very rare.

Like any medicine, there's a very small chance that the hepatitis B vaccine could cause a serious reaction. Keep in mind that getting the hepatitis B vaccine is much safer than getting hepatitis B. Learn more about vaccine side effects.